xref: /aosp_15_r20/external/skia/docs/examples/Matrix_invert.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1*c8dee2aaSAndroid Build Coastguard Worker // Copyright 2019 Google LLC.
2*c8dee2aaSAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3*c8dee2aaSAndroid Build Coastguard Worker #include "tools/fiddle/examples.h"
4*c8dee2aaSAndroid Build Coastguard Worker REG_FIDDLE(Matrix_invert, 256, 128, false, 0) {
draw(SkCanvas * canvas)5*c8dee2aaSAndroid Build Coastguard Worker void draw(SkCanvas* canvas) {
6*c8dee2aaSAndroid Build Coastguard Worker     const SkPoint src[] = { { 10, 120}, {120, 120}, {120, 10}, {  10, 10} };
7*c8dee2aaSAndroid Build Coastguard Worker     const SkPoint dst[] = { {150, 120}, {200, 100}, {240, 30}, { 130, 40} };
8*c8dee2aaSAndroid Build Coastguard Worker     SkPaint paint;
9*c8dee2aaSAndroid Build Coastguard Worker     paint.setAntiAlias(true);
10*c8dee2aaSAndroid Build Coastguard Worker     SkMatrix matrix;
11*c8dee2aaSAndroid Build Coastguard Worker     matrix.setPolyToPoly(src, dst, 4);
12*c8dee2aaSAndroid Build Coastguard Worker     canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, src, paint);
13*c8dee2aaSAndroid Build Coastguard Worker     canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, dst, paint);
14*c8dee2aaSAndroid Build Coastguard Worker     paint.setColor(SK_ColorBLUE);
15*c8dee2aaSAndroid Build Coastguard Worker     paint.setStrokeWidth(3);
16*c8dee2aaSAndroid Build Coastguard Worker     paint.setStrokeCap(SkPaint::kRound_Cap);
17*c8dee2aaSAndroid Build Coastguard Worker     canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, dst, paint);
18*c8dee2aaSAndroid Build Coastguard Worker     if (matrix.invert(&matrix)) {
19*c8dee2aaSAndroid Build Coastguard Worker         canvas->concat(matrix);
20*c8dee2aaSAndroid Build Coastguard Worker         canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, dst, paint);
21*c8dee2aaSAndroid Build Coastguard Worker     }
22*c8dee2aaSAndroid Build Coastguard Worker }
23*c8dee2aaSAndroid Build Coastguard Worker }  // END FIDDLE
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